worm

worm /n./ [from `tapeworm' in John Brunner's novel
"The Shockwave Rider", via XEROX PARC] A program that
propagates itself over a network, reproducing itself as it goes.
Compare virus. Nowadays the term has negative connotations,
as it is assumed that only crackers write worms. Perhaps the
best-known example was Robert T. Morris's `Internet Worm' of 1988,
a `benign' one that got out of control and hogged hundreds of
Suns and VAXen across the U.S. See also cracker, RTM,
Trojan horse, ice, and Great Worm, the.